Effects of plant growth regulators on in vitro cultured nodal explants of cassava (Manihot esculenta Crantz) clones

Abstract

Cassava (Manihot esculenta Crantz) is one of the major food security crops in Ethiopia. Recently, clean planting materials of improved cassava cultivars are in high demand. A limitation, however, is the low multiplication ratio (1:10) of the crop via conventional methods. Thus, a study was undertaken to develop an efficient in vitro mass propagation protocol for two elite cassava clones, 44/72-NR and 44/72-NW. Combination of different plant growth regulators (PGRs); four concentrations of 6-benzylaminopurine (BAP) and kinetin (Kin) on shoot multiplication and that of α-naphthaleneacetic acid (NAA) and BAP each at four concentration combination on root induction were assessed. The experiments were factorial laid out in a completely randomized design (CRD) with PGRs as one-factor and clones as another, replicated five times. Significant (p< 0.05) interaction effects were observed in response to shoot multiplication and root induction treatments within six weeks of culture. Murashige and Skoog (MS) medium containing BAP and Kin each at 0.75 mg/L gave an average of 7.30 shoots per explant than other media combinations. Consecutively, the regenerated cassava shoots produced an average of 6.14 roots within four weeks in a 0.5 mg/L NAA medium and were successfully acclimatized and transferred to field.

Keywords: Cassava, Manihot esculenta, clone, in vitro, nodal bud, plant growth regulators.

African Journal of Biotechnology Vol 13(28) 2830-2839